Jan. 12, 2011 -- The marketing for controversial at-home genetics kits claim to empower users with the information they need to take steps to improve their health. But a new study suggests that, in the short term at least, the tests have little impact on behavior.

Known as direct-to-consumer genetic tests, the kits claim to provide consumers with actionable information about their risk for disease from a simple saliva sample mailed to the labs of the companies that sell them.

But the tests have come under fire from federal officials and were the subject of a congressional hearing last summer following the release of a Government Accountability Office report concluding that they often provide misleading information to consumers.

Impact of at-Home Genetics Test

The new study, which appears in the New England Journal of Medicine, does not directly address the clinical usefulness of the direct-to-consumer genetics tests. Rather, researchers wanted to know how the people who used them processed and acted on the information the tests provided.

The study included just over 2,000 people followed for three months after taking the direct-to-consumer test Health Compass, sold by the California-based company Navigenics.

A year's subscription to the testing service costs about a thousand dollars, but the study participants received the subscription at a discounted rate.

The study measured anxiety levels and test-related actions among the participants after they learned the results of their DNA screening.

A major concern is that the tests will increase health-related anxiety among the people who use them, study researcher Cinnamon S. Bloss, PhD, tells WebMD.

Bloss is an assistant professor of the Scripps Translational Science Institute in La Jolla, Calif.

Nine out of 10 study participants reported no result-related stress three months after having the test, and there was little evidence of an increase in doctor-provided screening.

While about half of the participants said they planned to have medically delivered screening tests with greater frequency due to the DNA findings, Bloss says there was no evidence that they had done so.

Participants Didn't Change Lifestyle

There was also little evidence that the people in the study made healthier lifestyle choices, such as exercising more and eating better, after learning their DNA results.

The researchers will continue to follow the study participants in an effort to determine the longer-term impact, if any, of saliva-based at-home DNA screening on behavior and stress levels.

Medical ethicist Ana Iltis, PhD, who directs the Center for Bioethics, Health and Society at Wake Forest University, says the findings suggest at-home genetics kits provide no short-term risks or benefits in educated populations like the one included in the study.

All the study participants were employees of health or technology companies.

"The bottom line is there appears to be nothing to be terribly afraid of and nothing to be gained from these tests in the short term," she says. "But the findings also suggest that if we are interested in promoting healthy behaviors, this is probably not the way to do it."

Usefulness of Tests

University of North Carolina, Chapel Hill professor of Genetics James Evans, MD, says companies like Navigenics, 23andMe and Pathway Genomics, which market the at-home kits, definitely promote the idea that the tests will lead to better health.

The Navigenics web site makes this clear: "Our goal is to empower you with genetic insights to help motivate you to improve your health," the company's home page states.

"These kits are explicitly and implicitly appealing to the idea that knowledge is power," Evans says. "The reality is that there are no shortcuts to changing behavior. You can't wave a genetic magic wand and get people to eat right and exercise."

In its investigation of the at-home genetics kits, the GAO concluded that marketing claims were misleading and that the tests were of little practical use to consumers.

Evans says this is largely due to the fact that there is as yet no accurate way to assess disease risk based on their findings.

"Even once we are able to do this, I suspect that the magnitude of risk conferred will be so small as to be trivial," he says. "Most diseases have many components and genetics is only one of them."

Navigenics Responds to Study

The study was paid for, in part, by grants from the National Institutes of Health, but Navigenics provided the test kits to the Scripps researchers.

A news release issued by the company Tuesday focused on the finding that study participants did not experience heightened anxiety in the months after having the screening test.

The company provided access to genetic counselors to help participants interpret the test results, as it does for all its customers, but only 10% of the people enrolled in the study took advantage of this.

This low utilization rate led to policy changes within the company, according to Navigenics Vice President of Genomic Services Elissa Levin, MS.

"We now proactively reach out to every individual who completes Navigenics' risk assessment, and, as a result, the majority now undergo genetic counseling, which is offered to all customers at no additional cost," she notes in the release.